Final answer:
Scientists get water by breaking up Antarctic ice because it contains a large amount of Earth's fresh water, which is accessible in solid form. Ice cores from these areas also provide valuable data on past climate conditions, making them important for climate change research.
Step-by-step explanation:
The fact that scientists obtain water by breaking up chunks of ice in Antarctica indicates that the ice there is primarily composed of fresh water. In fact, the ice sheet covering Antarctica is substantial, extending more than a mile thick and holding about 70% of the Earth's fresh water, despite Antarctica being classified as a desert due to its low precipitation levels. Furthermore, the ice cores drilled in Antarctica, such as those from the Russian Vostok station, can reach depths of over 3,000 meters and have trapped carbon dioxide and isotopes like deuterium, providing data for analyzing past atmospheric CO₂ concentrations and temperature changes over a span of 420,000 years. This information is critical for understanding climate change attributed to increases in greenhouse gases, including carbon dioxide from burning fossil fuels.